Remove leading zeroes from Binary converted from Decimal

I am solving a problem where I have to convert given first N natural numbers to binary numbers. I am using bitset and .to_string(). But, after the number is converted to binary it has some leading zeroes obviously as equal to the size of the given bitset. The task is to remove that. I have done that using std::string:: erase() But I think it's not a good approach to do so. How can I optimize this part of the code?

#include <iostream>
#include <bitset>
#include <string>
int main()
{
    int T;
    std:: cin >> T;
    while(T--) {
    int n;
    std:: cin >> n;
    for(auto i = 1; i <= n; ++i) {
        std::string binary = std::bitset<32>(i).to_string(); //to binary

        //This part here

        int j = 0;
        while(binary[j] == '0') {
            ++j;
        }
        binary.erase(0, j);

        //Till here

        std::cout<<binary<<" ";
    }
    std:: cout << std:: endl;
    }
    return 0;
}

Solution

You could make use of the std::string::find_first_not_of() function to get the position of the first character that isn't a zero. Then use std::string::erase() to erase from the beginning of the string (index 0) to the position of the first non-zero character. This will avoid the while loop you're currently using.

Example:

std::string binary = std::bitset<32>(128).to_string(); //"00000000000000000000000010000000"
binary.erase(0, binary.find_first_not_of('0')); //"10000000"
std::cout << binary;